<html>

	<head>
		<style>
			.a {
				background-image: url(../img/page/yenei_04_14.png);
			}
			/*div{
				width: 300px;
				height: 56px;
			}*/
			.b {
				background-image: url(../img/page/yenei_04_14.png);
			}
			/*body{
				background-color: skyblue;
			}*/
		</style>
		<script>
			var i = 0;

			function change() {
				if(i) {
					document.getElementById("btn").className = "a";
					i = 0;
				} else {
					document.getElementById("btn").className = "b";
					i = 1;
				}
			}
		</script>
	</head>

	<body>
		<!--<input id="btn" type="button" class="a" value="click me" onClick="change()">-->
		<div type="button" id="btn"  class="a" onClick="change()"><img src="../img/page/yenei_04_20.png" alt="" /></div>
	</body>

</html>